Such an arrangement is disclosed in U.S. Pat. No. 4,951,188 wherein an electric drive in combination with an internal combustion engine is described. The drive is driven via an output stage configured as a bridge circuit. The output stage is configured as a bridge circuit having four drivable power switches with the electric drive being arranged in the bridge diagonal. The electric drive is controllable in the forward direction as well as in the rearward direction in that in the corresponding switch-on phase one particular bridge diagonal is made conductive. Furthermore, switching means are provided which permit the function of the output stage and electric drive to be monitored with respect to short circuits or shunts and/or overcurrents in the region of the output stage and electric drive.
Monitoring in this manner generates an alarm signal for a fault condition independently of the magnitude of the drive signal. The formation of the alarm signal and the reaction which follows must therefore be designed for the worst possible fault.